Improvement in piston-packings



".A. E. BAKER. Pistn-Packings.

No.l47,543. PatentedFemmsM.

WITNESSES. 11m/mma.

z5 @mv UNITED STATES PATENT (DEEICEo AUGUSTUS E. BAKER, OF PROVIDENCE, RHODE ISLAND.

lMPROVEMENT IN PISTN-PACKINGS.

Specification forming part of Letters Patent No. 147,543, dated February 17, 1874; application filed July 26, 1873.

lo all whom it may concern:

Be it known that I, AUeUsTUs E. BAKER, of the city and county of Providence, in the State of Rhode Island, have invented certain new and useful Improvements in Piston-Packings and I do hereby declare that the following specification, taken in connection with the drawings making a part ofthe same, is a full, clear, and exact description thereof.

My invent-ion relates to that class of pistonpaekings in which the packiiig-rings are dis- Tended against the surface of the cylinder by the direct pressure of the steam.

A in the several figures represents the piston-rod, which is-secured to a four-arm sawbuck or other equivalent shaped head, B, and circular plate F. C is the chunk-ring, which is combined with the central head B by means of a pointed holdingscrew, D, hereafter to be referred to. The 'chunk-ring is furnished with two sets ot' expanding-rin gs, one for each side ot' the piston. Each set of rings is made up of two members, (rings broken at one point cnly,) a and b, shown in section at Fig. 4, which, together, make a continuous ring, but the member a is lipped so as to receive the member b, Fig. 4, and the joint in each 1nember is covered .by the other member, the two members being doweled together, so that as a whole the packing-ring may turn around the chunk-ring, but the relation ot' the two parts of the ring to each other will not be thereby changed. Upon both sides of the chunk-rings recesses or chambers E are made, within which recesses springs are placed so as to press the packing-rings outward against the surface ot' the cylinder; but the springs are not relied 011 to eiect a tight joint, but are intended merely to keep the rings at all times bea-rin g against the cylinder.

It will be noticed that the springs s are so shaped as not to interfere with the packingrings turning around the chunk-ring, and it is intended that the rings shall be free to be constantly slowly revolvin g around th e chunk-ring for the purpose of diminishing the tendency of them to wear away unerenly.

The front face ot the pist-on is covered with a cap, F, Fig. 2, secured by screw-bolts to the head R, and the other face by the plate F to which the head B is cast, and through which cap and plate holes c are made for the admission of steam alternately to the chambers E on opposite sides of the piston for pressing out the packingrings to make a tight joint with the interior surface of the cylinder.

From the foregoing description, it will be understood that although the packing-rings appropriate to each side of the piston are pressed outward by the direct action of the steam, the rings themselves are free to more around the chunk-ring, and the said rings, being composed of two members, a and-b, constructed and arranged relative to each other, as described, it is impossible, if the piston is properly constructed, for the steam to blow through from one side to the other.

The head B is combined with the chunk-rin g by means of the pointed holding-screw D and nut c. rl'he length of the opposite radial arms l of the head B is less than the diameter of the circular recess G in the chnnk-ring which receives the said head, and by slackeningthe screw D the chunk-ring can be adjusted to a new position, relatively to the head B, and the two again secured together by entering the point ot D in another socket-hole'. This arrangement is of advantage in making a nice adjustment of the piston to the cylinder and the stuffing-box of the front head.

fh-at I claim as my invention, and desire to secure by Letters Patent, is

1. Expansible packing-rings a b, in combination with a chunk-ring, O, provided with chambers E, when such packing-rings are arranged to turn around the chunk-ring, substantially as described.

2. The combination of the head B, recessed chunk-rin g C, and holding-screw D, substantially as described.

AUG UCTUS E. BAKER. Witnesses EDwTN G. PrERcE,

TnoMAs F. GoseRorE. 

